Apple iPhone Duo Review: The Big Screen You'll Actually Carry

You don't need a power-user excuse to want this iPhone

You don't need to edit movies or run a business from your phone to want the iPhone Duo. You only need to be someone whose phone is where a lot of ordinary life happens: the article you read on the couch, the school forms, the shopping, the photos from last weekend that you still haven't sorted.

The Duo is Apple's first foldable iPhone. It opens from a conventional cover display to a wider-than-tall inner screen. You still use iOS, not iPadOS. That matters: you're buying a roomier version of your phone, not a full iPad that happens to fit in a pocket.

We think that's a perfectly good reason to spend money. Reading, browsing and looking at photos aren't lesser uses that need a productivity excuse. If those are what fill your phone hours, a better screen for them is as sensible a purchase as a better camera is for someone who lives behind the shutter.

At $1,999 for 256GB, it's Apple's most expensive iPhone, and the cameras and chip alone don't explain that. The inner screen has to earn it. For the right person, it does.

The real benefit is keeping related things in view

Size is the obvious selling point, but it isn't the most interesting one. The Duo's real advantage is that you stop having to decide what disappears. A conventional iPhone shows one thing well. Anything else you need has to live in your memory until you switch back to check it.

Picture a medical bill in your email beside the insurer's explanation of benefits saved as a PDF in another compatible app. On a conventional phone, you check a line in one, switch apps, find the matching line in the other, forget the amount, switch back. With both open on the Duo, you can run down them together. The task isn't advanced. It's just one that ordinary phones make tedious.

That said, two apps aren't automatically the best use of the space. Split View gives each app a narrower column, so you gain comparison and lose some breadth. For anything you want to sink into, such as a long article, a recipe collection or a map, one app across the whole inner screen is often better. The pleasure of the Duo is that you can choose either.

What you get from a single big view varies, too. Depending on the app's layout and your settings, a larger screen shows the same content larger or shows more of it at a similar size. More context is usually the better prize: you keep the paragraph before the one you're reading, or the neighborhood around your route.

The cover screen matters every time you don't unfold it

A foldable spends much of its day shut, and the cover screen is where you'll pay for the Duo's design most often. Closed, it's wider and thicker than the Pro Max, and the cover screen is shorter and squarer. That shape leaves the keyboard crowded vertically, as Ars Technica found. Notifications, payments and short replies are fine. Longer messages will have you opening the phone, which is an extra step every time.

Count those openings as part of the design, not a nuisance you can wish away. Opening it for a better view is a fair trade. Having to open it just to finish routine replies comfortably is a different proposition. For a day dominated by those short exchanges, we'd choose the Pro Max.

Unlocking changes too. There's no Face ID; Touch ID lives in the side button and works open or closed. Expect it to feel different if you're used to looking at your phone to unlock it.

Opening the phone helps typing, but it doesn't turn the Duo into a writing machine. The keyboard still takes a large share of the screen, and Tom's Guide found that rotating a landscape Split View pair into portrait temporarily leaves you with one app until you turn back. So a taller keyboard view and two apps don't come together easily. The Duo is excellent for answering something with the source beside you and poor value as a way to draft long documents. If writing at length on your phone is the reason you're tempted, keep your money.

Apple Pencil (USB-C) support arrived with iOS 27.2 as a separate purchase; Pencil Pro isn't supported. It's useful for signing a form or circling something on a PDF, not a reason to buy on its own.

An uncertain failure rate, but a very personal cost of disruption

Shortly after launch, some owners reported cracks in the inner display. Apple told TechRadar it was aware of an issue affecting a small number of units and directed affected customers to AppleCare for replacement. It hasn't disclosed how many units are affected or the cause, and nothing in that reported response says a paid plan is required.

iFixit's teardown found dust reaching moving hinge parts in a fluorescent-powder experiment and proposed a stress point in the display support as one possible explanation. That's a hypothesis, not a confirmed cause, and the experiment isn't a certification test. The Duo's IP68 rating covers dust and water in lab conditions; it says nothing about how the hinge ages. iFixit's provisional 5 out of 10 repairability score points to straightforward battery work but a complicated display and hinge.

Two separate questions are useful here. How likely is a failure? We don't have a public failure rate yet. What would one cost you? That varies enormously. For someone with a work phone, a spare or a flexible week, a replacement is an annoyance. For someone travelling alone with one phone holding tickets, maps and payments, it's a real problem. Careful handling is sensible, but it cannot rule out a fault whose cause remains unknown.

The screen's appeal doesn't settle the timing question. We would buy now if the everyday benefits are compelling and a replacement would be manageable. If this will be your only phone on a long trip, we'd wait for clearer information. A backup changes the consequences of a fault, not its likelihood.